The standard distribution of Fedora 10 does not support the mp3 music format. While it does support many other great formats, like ogg, that are technically better than mp3, if you have mp3's it's kind of a pain that it doesn't support this out of the box.

If you want mp3 support in Fedora 10, it's not hard to add it. First close all of you music/media apps that are running (since we'll be updating them to support mp3). Then open a terminal window and enter the following commands:

rpm -ivh http://download1.rpmfusion.org/free/fedora/rpmfusion-free-release-stable.noarch.rpm

rpm -ivh http://download1.rpmfusion.org/nonfree/fedora/rmpfusion-nonfree-release-stable.noarch.rpm

yum -y install gstreamer-plugins-bad gstreamer-plugins-ugly xine-lib-extras-nonfree

yum install xmms xmms-mp3

Once these installs are done, your system should have the mp3 support that you want.